This invention generally relates to a reactive distillation process and system for the alkylation of aromatic compounds with olefins.
Alkylated aromatics, including linear alkyl benzenes (LAB's) having long chains (typically 10-14 carbons), are commonly used, commercial products. LAB's are commonly sulfonated to thereby produce surfactants.
Typically, alkylated aromatics are manufactured commercially using classic Friedal-Crafts chemistry, employing catalysts such as aluminum chloride, or using strong acid catalysts such as hydrogen fluoride, for example, to alkylate benzene with olefins. While such methods produce high conversions, the selectivity to the 2-phenyl isomer is low, generally being about 30% or less. LAB's with a high percentage of the 2-phenyl isomer are highly desired because such compounds when sulfonated have long "tails" which provide enhanced solubility and detergent properties.
Reactive distillation methods for producing short chain alkylated aromatics are known. These methods are typically directed toward reacting gaseous phase short chain olefins, such as ethylene or propylene, with benzene.